Securities - Securities with Unrealized Losses (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, fair value	$ 31,706	$ 285,714
Less than 12 months, unrealized loss	(326)	(5,681)
12 Months or more, fair value	1,093,307	1,070,442
12 Months or more, unrealized loss	(235,917)	(273,485)
Total fair value	1,125,013	1,356,156
Total unrealized loss	(236,243)	(279,166)
Obligations of State and Political Subdivisions
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, fair value	4,894	13,249
Less than 12 months, unrealized loss	(107)	(231)
12 Months or more, fair value	447,248	445,264
12 Months or more, unrealized loss	(120,220)	(124,584)
Total fair value	452,142	458,513
Total unrealized loss	(120,327)	(124,815)
MBS/CMO
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, fair value	3,745	176,333
Less than 12 months, unrealized loss	(42)	(2,461)
12 Months or more, fair value	484,310	480,235
12 Months or more, unrealized loss	(86,372)	(113,254)
Total fair value	488,055	656,568
Total unrealized loss	(86,414)	(115,715)
US Gov’t Sponsored Entities & Agencies
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, fair value	23,067	96,132
Less than 12 months, unrealized loss	(177)	(2,989)
12 Months or more, fair value	161,749	144,943
12 Months or more, unrealized loss	(29,325)	(35,647)
Total fair value	184,816	241,075
Total unrealized loss	$ (29,502)	$ (38,636)